Reinforced container



ug. 7, 1945- v M. o. KUHN 2,381,396

REINFORCED CONTAINER Filed Dec. 22, 1943 Patented Aug. 7, 1945 UNITEDSTATES PATENT OFFICE 2,881,396 REINFORCED CONTAINER Max 0. Kuhn,Cuyahoga Falls, Ohio, asslgnor to The Firestone Tire & Rubber Company,Akron, Ohio, a corporation ,of Ohio Application December 22, 1943,Serial No. 515,313

3 Claims.

This invention relates to containers for the transportation and storageof fluids under high pressure, and more especially it relates tocontainers of the character mentioned that are reinforced in a manner:that obviates shattering thereof upomrufiture ofs-the walls thereof.

The invention is of primary utility in its application to the oxygentanks carried by aircraft that are required to ascend to high altitudes,which oxygen is required to sustain life in rarefied atmosphere. Inmilitary aircraft subject to gunfire, the puncturing of an oxygen tankis attended with considerable hazard 'due to the expansive force of thereleased oxygen, which rends the container wall and may impellfragmentsthereof with great force for a considerable distance. My copendingapplication for Letters Patent, Serial No. 421,307, filed December 2,1941, now-Patent No. 2,339,554, issued January 18, 1944, disclosesbroadly a container for fluid under pressure reinforced in a manner tolocalize a breach in its wall resulting from puncture thereof and topre-- vent fragmentation, and it is to further improvement of this typeof container that this invention primarily is directed.

As previously constructed, the container comprised a hollow, sheet metalcylinder having closed ends of dome or generally hemi-spherical shape.The cylinder was externally reinforced with metal straps that werewelded thereto along their respective centerlines, some of said strapsextending longitudinally of the container and some extendingcircumferentially thereof. The latter consisted either of a plurality ofindividual straps that circumscribed the container, or a single metalstrap that was wrapped helicalLv about the container. In either case thecircumferential straps did not extend much beyond the medial cylindricalportions of the container. The longitudinally extending straps overlaythe circumferential straps and extended onto the end-domes of thecontainer, but did not extend to the axis thereof, being terminatedabout one half of the distance from the cylindrical portion of thecontainer to the axis of the domes.

It is well known that in containers of theshape described, the stress inthe material of the walls resulting from internal fluid pressure is notuniform, but is greater in the circumferential direction than in thelongitudinal direction; more specifically the degree of stress in thecylindrical wall of the container is substantially twice as aircraftwere equipped with nothing heavier than caliber machine guns. With theadvent of 50 caliber machine guns and 20 mm. cannon, the problem ofreinforcing the end-domes of the container is presented since thedestructive effect of the larger projectiles is much greater.Accordingly one of the objects of this invention is to provide in asimple and efficient manner for the reinforcing of the end-domes ofcontainers of the character mentioned to prevent shattering thereof whenpenetrated by the larger projectiles mentioned.

Other objects of the invention are to provide improved construction forreinforcing straps of the container to prevent tearing of the containerwall against the margins thereof during rending of said wall after beingpunctured; and toprovide greater safety to the personnel of combataircraft. Other objects will be manifest as the description proceeds.

Of the accompanying drawing:

Fig. 1 is a side elevation of a reinforced hollow container embodyingthe invention;

Fig. 2 is an end elevation of the same as viewed from the left thereof;and I Fig. 3 is a section, on a larger scale. on the line 3-3 of'Fig. 1.

Referring to the drawing, especially Figs. 1 and 2 thereof, it will beseen that the improved container comprises a hollow body or shell IIthat has a central region of cylindrical shape and respective endregions ofhemi-sphericai or dome shape. The shell i0 is composed ofsheet metal,

stainless steel being referred because of its durability and strength,but other metals equally'suitable may be employed if desired. The shellper se may be manufactured in any known or pre-- ferred manner, and nonovelty therefor isasserte'd herein. One of the end-domes of the shellis axially apertured and provided with a threaded fixture or coupling IIby which a suitable pipe or conduit is attached for enabling thecontainer to be charged or discharged.

The shell II is exteriorly reinforced by metal straps that extendcircumferentialiy and longi tudinally thereof. The circumferentialreinforcement as shown comprises a strap II that extends helicallyaround the shell, the terminal portions of the strap I! being disposedupon the reportion, of the shell. If desired. the single strap It may bereplaced by a plurality of individual straps, each extendingcircumferentially ot the shell with its opposite ends in abuttingrelation. The strap I8 is transversely flat, and is permanently securedto the shell I. by being electrically welded thereto, the welding beinglocally effected along the longitudinal centerline of the strap.Reinforcing the opposite end-domes of the shell I. are respective strapsit. Each strap ll extends along a meridian line around the dome, aboutone half of the distance from the axis of the latter to the nearestconvolution of the strap ll measured on the surface of the dome. Thestraps II are flat in transverse section and preferably endless, and arewelded to the shell in the same manner as the strap it.

The longitudinal reinforcement of the shell ll comprises a plurality ofmetal straps II, it. As shown herein, the straps I are six in number,but a greater or fewer number may be employed depending upon thediameter of the container. Preferably each strap It consists of twolongitudinal sections, which sections are Joined endto-end by a flatcoupling sleeve ii. The straps it overlie the respective convolutions ofthe strap ll, their end portion extending onto the domeends of the shelland terminating in abutting relation to the near margins of thedome-rings M. The straps it are permanently attached to the shell it .bybeing electrically welded thereto locally along their respectivecenterline, as indi-- cated at I9, Fig. 3.

A salient feature of the invention is the novel cross-sectional shape ofthe straps l8. Whereas similar straps of the oxygen containersheretofore provided were formed with upstanding marginal flanges, themarginal portions of the straps it are bent outwardly and backwardly sothat they overlie the body of the strap, in slightly spaced relationthereto, the raw edges of the strap being in confronting relation. Theconstruction is best shown in Fig. 3 wherein the folded marginalportions of a strap it are shown at "a, "a. The arrangement is such thatthe lateral marginal portions of the strap are rounded on a radius thatis greater than the thickness of the metal of which the strap iscompoud.

The straps l3, l4 and I8 divide the surface of the container intorelatively small areas in which breaches in the container wall, arisingfrom puncture thereof, are localized. Thus when any portion of thecontainer wall is punctured, the pressure of the escaping gaseous fluidenlarges the puncture by rending and tearing the metal in alldirections.When a tear reaches the strap I: or II it doesnot pass the same, butmayfollow the strap due to the shearing action of the raw marginthereof, the action being similar to the tearing of paper along astraight edge pressed thereupon. But tears that intersect thelongitudinal straps ll, eitherdirectly or by way of the straps ll, ll donot follow said straps ll. This is because of the rounded or curledlateral margins thereof which enable the ruptured containerwall to bendor fold thereover without tearing, as is indicated in broken lines inFig. 3.

".lhe invention involves no radical departure from prior construction,yet it achieves the several advantages set out in the foregoingstatement of oblccts. By limiting tearing of the container well afterpuncture, fragmentation thereof is obviated and the hazard to craft andpersonnel from flying metal is abated. Although the extremities of thecontainer are not as extensively reinforced as the remainder thereof,this is not. of great importance since the stress in the domes oi thecontainer is much less than in its cylindrical portion, and the ends ofthe container are less exposed to gunfire. The curled edges of the 1straps l6 not only strengthen them, but also improve the appearance ofthe container.

Modification may be resorted to without departing from the spirit of theinvention or the scope thereof as defined by the appended claims.

What is claimed is:

1. In a container for fluid under pressure, the combination of a hollowmetal shell of general cylindrical shape having dome-like hemi-sphericalends, and metal straps secured to the outside of the shell and extendingcircumferentially and longitudinally of the shell so as to divide thesur face thereof into relatively small areas wherein shattering islocalized in case or rupture of the container wall, said straps beingwelded to the container shell solely along the longitudinal centerlinesof the straps and spaced from the lateral margins thereof, the strapsextending in one direction at least having their marginal portionsfolded voutwardly and over the body portion with the respective edges ofeach strap in confronting relation, to prevent tearing of the containerwall along the margins of said folded straps.

2. In a container for fluid under pressure, the combination of a hollowmetal shell of general cylindrical shape having dome-like hemisphericalends, and metal straps secured to the outside of the shell and extendingcireumferentially and longitudinally or the shell so as to divide thesurface thereof into smaller areas wherein shattering is localized incase of rupture of the container wall, said straps being welded to thecontainer solely along their longitudinally centerlines in spacedrelation to their lateral margin l portiom, the circumferential strapscomprising a strap extending helically about the cylindrical portion ofthe container and terminating near the respective junctures oi the enddomes with the cylindrical portion, and endless straps disposed solelyon the end domes and encircling the latter along meridian lines thereon,the longitudinal straps terminating in abutting relation to said domestraps.

3. A combination as defined in claim 2 wherein the longitudinal strapsand the endless domestraps have their marginal portions folded outwardly and over the body portion with the respective edges of each strapin confronting relation to prevent tearing of the container wall alongthe margins of said folded straps.

MAXO. KUHN.

